Quantitative Proteomics of Hepatic Drug‐Metabolizing Enzymes and Transporters in Patients With Colorectal Cancer Metastasis

Abstract

The impact of liver cancer metastasis on protein abundance of 22 drug-metabolizing enzymes (DMEs) and 25 transporters was investigated using liquid chromatography-tandem accurate mass spectrometry targeted proteomics. Microsomes were prepared from liver tissue taken from 15 healthy individuals and 18 patients with cancer (2 primary and 16 metastatic). Patient samples included tumors and matching histologically normal tissue. The levels of cytochrome P450 (CYPs 2B6, 2D6, 2E1, 3A4, and 3A5) and uridine 5′-diphosphoglucuronosyltransferases (UGTs 1A1, 1A6, 1A9, 2B15, 2B4, and 2B7) were lower in histologically normal tissue from patients relative to healthy controls (up to 6.6-fold) and decreased further in tumors (up to 21-fold for CYPs and 58-fold for UGTs). BSEP and MRPs were also suppressed in histologically normal (up to 3.1-fold) and tumorous tissue (up to 6.3-fold) relative to healthy individuals. Abundance of OCT3, OAT2, OAT7, and OATPs followed similar trends (up to 2.9-fold lower in histologically normal tissue and up to 16-fold lower in tumors). Abundance of NTCP and OCT1 was also lower (up to 9-fold). Interestingly, monocarboxylate transporter MCT1 was more abundant (3.3fold) in tumors, the only protein target to show this pattern. These perturbations could be attributed to inflammation. Interindividual variability was substantially higher in patients with cancer. Proteomics-informed physiologically-based pharmacokinetic (PBPK) models of 50 drugs with different attributes and hepatic extraction ratios (Simcyp) showed substantially lower drug clearance with cancer-specific parameters compared with default parameters. In conclusion, this study provides values for decreased abundance of DMEs and transporters in liver cancer, which enables using population-specific abundance for these patients in PBPK modeling.Colorectal cancer is the second most lethal type of cancer, 1 presenting with metastases to the liver in half of the patients, 2 which leads to poor prognosis. 3 Genetic and epigenetic alterations contribute to its manifestation. 4 Colorectal liver metastasis (CRLM) originates from the colon and metastasizes to the liver through the portal vein, whereas primary liver cancer has hepatic origin. Primary

Proteomic quantification of receptor tyrosine kinases involved in the development and progression of colorectal cancer liver metastasis

“…Liver tissue was prepared into microsomes, as previously described ( 28 – 30 ). Briefly, liver tissue was homogenized using a Fisherbrand 150 Handheld Homogenizer (Thermo Fisher Scientific, UK) in homogenization buffer (150 mM KCl, 2 mM EDTA, 50 mM Tris, 1 mM dithiothreitol, and EDTA-free protease inhibitor cocktail, pH 7.4) at 10 ml per gram of liver tissue.…”

The Role of Solute Carrier Transporters in Efficient Anticancer Drug Delivery and Therapy

“…In addition to their presence in normal tissues, the expression of these transporters has been found to be up- or down-regulated in certain cancers ( Table 1 ). Thus, OATP1A2 absolute protein expression has been found to be lower in liver cancer metastases compared to in histologically normal tissue [ 55 ]. Moreover, OATP1A2/SLCO1A2 and OATP1B3/SLCO1B3 mRNA and protein expression was significantly higher in malignant breast cancer tissue as compared to the surrounding non-malignant tissue [ 56 , 57 ].…”

“…Liver-specific OATP1B1 and OATP1B3 play important roles in the elimination of metabolites and xenobiotics from the body. However, liver cancers such as hepatocellular carcinoma and colorectal carcinoma liver metastases have an intrinsically low expression of these transporters [ 55 , 60 ], as they do not transport substrates, which are necessary for the survival of this type of cancer cell. This is a challenge in terms of drug delivery into liver tumors, as many drugs are substrates of OATP1B1 and/or OATP1B3.…”

“…For OCT3, a high protein expression was detected in the head and neck squamous cell carcinoma and colorectal carcinoma [ 82 , 83 ]. In contrast, a low absolute protein expression of OCT3 was measured in colorectal carcinoma liver metastases [ 55 ]. In addition, a low OCT3/SLC22A3 expression was found in hepatocellular carcinoma (on protein level) and in cholangiocellular carcinoma (on the protein and mRNA levels) [ 69 , 84 ].…”

“…SLC22A6-8 mRNA expression was found be lower in kidney renal cell carcinoma and kidney renal papillary cell carcinoma as compared to in normal tissues [ 102 ]. In addition, the absolute protein expression of OAT2 was lower in colorectal carcinoma liver metastases compared to in non-cancerous tissue [ 55 ].…”