Abstract 2201: Effect of opioid and cannabinoid receptors gene expression on survival of patients with colorectal cancer
Authors: Vidlarova Monika , Srovnal Josef , Berta Emil , Gurska Sona , Rehulkova Alona , Kourilova Pavla , Hajduch Marian 
Published: April 2023

Abstract
Introduction: Colorectal cancer (CRC) is one of the leading causes of cancer death in the world. CRC patients are often treated with opioid (e.g., morphine, or synthetic opioid piritramide) analgesia for pain, nausea, and side effects of chemotherapy. These analgesics act through opioid and cannabinoid receptors, which pathways are involved in tumor progression and metastases and thus can negatively affect the survival of patients. In our previous studies, we analyzed the presence of circulating tumor cells (CTCs) in two groups of CRC patients. One group received morphine analgesia (MA) and second piritramide analgesia (PA). We found that MA associated with increased CTCs levels and significantly shorter cancer-specific survival (CSS). These findings lead to further analysis of the opioid and cannabinoid receptors tumor gene expressions. We expected that the different expression of specific receptors in tumor tissue makes a difference between the effects of MA and PA on patients´ survival.
Methods: Gene expression of opioid receptors µ (OPRM), κ (OPRK), δ (OPRD), nociceptin (OPRL) and cannabinoid receptors 1 and 2 (CB1, CB2) was analyzed in RNA purified from tumor tissues in 131 patients with CRC. Expression of markers was detected using real-time RT-PCR on LightCycler 1536 from Roche. Β-actin gene expression was used for gene expression normalization. Specific cut-off values were calculated for each marker using maxstat R software, ver. 3.3.1. Relationship between expression of receptors in tumor tissue and patients’ survival was analyzed using COX regression, Kruskal-Wallis/ANOVA test, and Kaplan-Meier method.
Results: In total, 118 patients (45 females and 73 males, average age 68 years), of clinical stage-III were analyzed. It was found that MA in CRC patients was associated with significantly shorter cancer-specific survival (CSS; p=0,027). The univariate survival analysis revealed that CRC patients with high OPRM tumor tissue gene expression had significantly longer overall survival (OS; p=0.017) and patients with CB2 gene expression had significantly longer disease-free survival (DFS; p=0,029). All other tested opioid receptors expressions had no statistically significant effect on patients’ survival.
Conclusion: The diverse opioid receptors’ expressions on tumor and immune cells can affect the survival of cancer patients treated with opioid analgesia. Morphine perioperative analgesia seems to shorten the CCS in CRC patients in our study. However, further research is required to elucidate the effect of opioids on different cell populations.
Acknowledgement: This study was supported by Ministry of Health of the Czech Republic [NV18-03-00470]; Palacky University Olomouc [LF 2022_012]; European Regional Development Fund [ENOCHCZ.02.1.01/0.0/0.0/16_019/0000868) and European Union - Next Generation EU (EXCELES LX22NPO5102).
Citation Format: Monika Vidlarova, Josef Srovnal, Emil Berta, Sona Gurska, Alona Rehulkova, Pavla Kourilova, Marian Hajduch. Effect of opioid and cannabinoid receptors gene expression on survival of patients with colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2201.