In vitro und in vivo Charakterisierung von KAN0438757 als Inhibitor des glykolytischen Enzyms PFKFB3 im kolorektalen Karzinom

In vitro and in vivo characterization of KAN0438757 as an inhibitor of the glycolytic enzyme PFKFB3 in colorectal cancer

by Tina Goldhardt
Doctoral thesis
Date of Examination:2023-08-29
Date of issue:2023-08-01
Advisor:PD Dr. Dr. Lena-Christin Conradi
Referee:PD Dr. Dr. Lena-Christin Conradi
Referee:Prof. Dr. Elisabeth Zeisberg
Persistent Address: http://dx.doi.org/10.53846/goediss-10030

 

 

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Abstract

English

Background: Colorectal cancer is the third most common cancer and the second leading cause of cancer-associated deaths worldwide. Despite early detection screening methods, approximately 25% of patients already have metastases at the time of diagnosis. Recommended treatment is radical surgical resection, including neoadjuvant radiochemotherapy in rectal cancer and adjuvant chemotherapy in stage II and higher stages. In treatment of metastatic carcinomas (stage IV), antibodies and inhibitors such as VEGF and EGFR are widely used. Unfortunately, resistance to established therapies often occurs in disease process, making it necessary to find new therapeutic targets and develop further inhibitors. As known, glycolysis is highly upregulated in tumor cells. It was previously shown that inhibition of the glycolytic enzyme PFKFB3 is a promising strategy to target tumor vascularization and tumor growth. PFKFB3 is increasingly expressed in tumor cells, tumor endothelial cells and healthy endothelial cells. Methods: In the present study, the newly developed PFKFB3 inhibitor KAN0438757 was evaluated in vitro on colorectal cancer cell lines (HT-29 and HCT-116) and endothelial cells (HUVECS) in terms of effectiveness on cell morphology, proliferation, viability, invasion and migration ability, and cell toxicity. In addition, tolerability was tested in vivo at various doses in tumor-free immunocompetent murine animal models. Complementary, first therapeutic experiments were performed in tumor-bearing murine xenografts to investigate the effects on tumor growth and tumor vasculature. Results: The in vitro experiments showed a significant decrease in cell viability, proliferation, migration rate and reduction capacity after treatment with KAN0438757 in a concentration-dependent manner. A relevant increase in cell death rate could be seen in tumor cells, whilst leaving non-transformed endothelial cells (HUVEC) basically unaffected. Interestingly, the invasion ability of tumor cells was significantly reduced independently of proliferation. Furthermore, in vivo experiments showed no relevant toxicity of KAN0438757 in short- or long-term treatment. As an initial therapeutic application, a low dosage of KAN0438757 was chosen. It could be demonstrated that KAN0438757 alone does not significantly affect tumor growth. However, immunohistochemical analysis of tumor tissue revealed a significantly increased rate of hypoxic areas and signs of tumor vessel normalization. Combination with standard chemotherapy (Oxaliplatin) indicated a potentially synergistic anti-tumor effect. Discussion: The results demonstrate the antiproliferative effect of KAN0438757 in vitro and promising chemosensitizing effects in vivo, without relevant toxicity. This highlights the inhibitor as an interesting target for further investigation in vivo. Further, combinations with other chemotherapeutics and radiotherapy should be evaluated to improve therapeutic strategies and overcome resistance in future.
Keywords: glycolysis; PFKFB3; KAN0438757; colorectal cancer; PDX; Tumor vessel normalization; Angiogenesis; Chemotherapy
Schlagwörter: Kolorektales Karzinom; Glykolyse; KAN0438757; PFKFB3; PDX; Tumorgefäßnormalisierung; Angiogenese; Chemotherapie
 
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